Diagonal of Rectangle
Calculate the diagonal of any rectangle using length and width with the Pythagorean theorem. Free online rectangle diagonal calculator for construction, framing, and geometry problems.
About This Calculator
The Diagonal of Rectangle Calculator computes the diagonal distance from one corner to the opposite corner using the Pythagorean theorem. This is essential for construction, woodworking, framing, and any project where you need to verify squareness or determine diagonal measurements.
The diagonal formula is d = sqrt(l^2 + w^2), where l is the length and w is the width. This derives from the Pythagorean theorem since the diagonal creates a right triangle with the sides of the rectangle. For example, a rectangle measuring 10 ft by 5 ft has a diagonal of approximately 11.18 ft.
Common Uses
- Construction: Check squareness of frames, foundations, and structures
- Woodworking: Calculate diagonal bracing lengths for cabinets and furniture
- Electronics: Determine screen sizes and display dimensions
- Education: Verify geometry homework and understand Pythagorean theorem applications
Frequently Asked Questions
How do you find the diagonal of a rectangle?
The diagonal of a rectangle is found using the Pythagorean theorem: d = sqrt(l^2 + w^2), where l is the length and w is the width.
What is the formula for the diagonal of a rectangle?
The formula is d = sqrt(l^2 + w^2). Square the length and width, add them together, then take the square root.
What is the diagonal of a 10 ft by 5 ft rectangle?
A rectangle with length 10 ft and width 5 ft has a diagonal of approximately 11.18 ft, calculated as sqrt(10^2 + 5^2) = sqrt125 ≈ 11.18.
Can I use this for construction projects?
Yes, this calculator is useful for checking squareness of frames, determining diagonal bracing lengths, and calculating material needs for rectangular structures.
Is this calculator free to use?
Yes, all calculators on Calculy are completely free to use with no registration required.
Can I share my calculation?
Yes, the URL saves your length and width inputs so you can bookmark or share the exact calculation.